Bell, Malcolm R.

Background: Although extracorporeal membrane oxygenation (ECMO) is used for hemodynamic support for in-hospital cardiac arrest (IHCA) complicating acute myocardial infarction (AMI), there are limited data on the outcomes stratified by the timing of initiation of this strategy. Methods: Adult (>18 years) AMI admissions with IHCA were identified using the National Inpatient Sample (2000–2017) and the timing of ECMO with relation to IHCA was identified. Same-day vs. non-simultaneous ECMO support for IHCA were compared. Outcomes of interest included in-hospital mortality, temporal trends, hospitalization costs, and length of stay. Results: Of the 11.6 million AMI admissions, IHCA was noted in 1.5% with 914 (<0.01%) receiving ECMO support. The cohort receiving same-day ECMO (N = 795) was on average female, with lower comorbidity, higher rates of ST-segment-elevation AMI, shockable rhythm, and higher rates of complications. Compared to non-simultaneous ECMO, the same-day ECMO cohort had higher rates of coronary angiography (67.5% vs. 51.3%; p = 0.001) and comparable rates of percutaneous coronary intervention (58.9% vs. 63.9%; p = 0.32). The same-day ECMO cohort had higher in-hospital mortality (63.1% vs. 44.5%; adjusted odds ratio 3.98 (95% confidence interval 2.34–6.77); p < 0.001), shorter length of stay, and lower hospitalization costs. Older age, minority race, non-ST-segment elevation AMI, multiorgan failure, and complications independently predicted higher in-hospital mortality in IHCA complicating AMI. Conclusions: Same-day ECMO support for IHCA was associated with higher in-hospital mortality compared to those receiving non-simultaneous ECMO support. Though ECMO-assisted CPR is being increasingly used, careful candidate selection is key to improving outcomes in this population.

Background: There are limited data on the epidemiology and timing of in-hospital death (IHD) in patients with acute myocardial infarction-cardiogenic shock (AMI-CS). Methods: Adult admissions with AMI-CS with IHDs were identified using the National Inpatient Sample (2000–2016) and were classified as early (≤2 days), mid-term (3–7 days), and late (>7 days). Inter-hospital transfers and those with do-not-resuscitate statuses were excluded. The outcomes of interest included the epidemiology, temporal trends and predictors for IHD timing. Results: IHD was noted in 113,349 AMI-CS admissions (median time to IHD 3 (interquartile range 1–7) days), with early, mid-term and late IHD in 44%, 32% and 24%, respectively. Compared to the mid-term and late groups, the early IHD group had higher rates of ST-segment-elevation AMI-CS (74%, 63%, 60%) and cardiac arrest (37%, 33%, 29%), but lower rates of acute organ failure (68%, 79%, 89%), use of coronary angiography (45%, 56%, 67%), percutaneous coronary intervention (33%, 36%, 42%), and mechanical circulatory support (31%, 39%, 50%) (all p < 0.001). There was a temporal increase in the early (adjusted odds ratio (aOR) for 2016 vs. 2000 2.50 (95% confidence interval (CI) 2.22–2.78)) and a decrease in mid-term (aOR 0.75 (95% CI 0.71–0.79)) and late (aOR 0.34 (95% CI 0.31–0.37)) IHD. ST-segment-elevation AMI-CS and cardiac arrest were associated with the increased risk of early IHD, whereas advanced comorbidity and acute organ failure were associated with late IHD. Conclusions: Early IHD after AMI-CS has increased between 2000 and 2016. The populations with early vs. late IHD were systematically different.

Background: With the rising cost of critical care and limited availability of critical care resources, improvements are need in the current cardiac intensive care unit (CICU) triage process. We sought to determine whether the Mayo Clinic Intensive Care Unit Admission Risk Score (M-CARS) could be used to predict which CICU patients will require critical care resources. Methods: Adult patients admitted to our CICU from 2007 to 2018 were retrospectively reviewed. The M-CARS was calculated using data from the time of admission. Groups were compared using Wilcoxon test for continuous variables and chi-squared test for categorical variables. Results: We included 12,428 patients with a mean age of 67 ± 15 years (37% females). The mean M-CARS was 2.1 ± 2.1, including 5,890 (47.4%) patients with M-CARS <2 and 644 (5.2%) patients with M-CARS >6. Critical care therapies were frequently used, including mechanical ventilation in 28.0%, vasoactive medications in 25.5%, dialysis in 4.8% and invasive lines in 44.3%. The low-risk cohort with M-CARS <2 was less likely to require invasive or noninvasive mechanical ventilation (8.0% vs. 46.1%), vasoactive medications (10.1% vs. 38.8%), dialysis (1.0% vs. 8.2%) or invasive lines (34.6% vs. 53.0%), as compared to patients with M-CARS ≥2 (all p<0.001). A higher M-CARS was associated with greater use of critical care therapies and longer CICU and hospital length of stay. Conclusions: In addition to predicting hospital mortality, the M-CARS predicts resource utilization during CICU admission and could be used in the triage of critically ill cardiac patients. Patients with M-CARS <2 infrequently require critical care resources and have extremely low mortality, yet account for nearly half of all CICU admissions, suggesting a potential to avoid CICU admission in many patients.

Abstract Aims The aim of this study is to evaluate the contemporary use of a pulmonary artery catheter (PAC) in acute myocardial infarction-cardiogenic shock (AMI-CS). Methods and results A retrospective cohort of AMI-CS admissions using the National Inpatient Sample (2000–2014) was identified. Admissions with concomitant cardiac surgery or non-AMI aetiology for cardiogenic shock were excluded. The outcomes of interest were in-hospital mortality, resource utilization, and temporal trends in cohorts with and without PAC use. In the non-PAC cohort, the use and outcomes of right heart catheterization was evaluated. Multivariable regression and propensity matching was used to adjust for confounding. During 2000–2014, 364 001 admissions with AMI-CS were included. PAC was used in 8.1% with a 75% decrease during over the study period (13.9% to 5.4%). Greater proportion of admissions to urban teaching hospitals received PACs (9.5%) compared with urban non-teaching (7.1%) and rural hospitals (5.4%); P &lt; 0.001. Younger age, male sex, white race, higher comorbidity, noncardiac organ failure, use of mechanical circulatory support, and noncardiac support were independent predictors of PAC use. The PAC cohort had higher in-hospital mortality (adjusted odds ratio 1.07 [95% confidence interval 1.04–1.10]), longer length of stay (10.9 ± 10.9 vs. 8.2 ± 9.3 days), higher hospitalization costs ($128 247 ± 138 181 vs. $96 509 ± 116 060), and lesser discharges to home (36.3% vs. 46.4%) (all P &lt; 0.001). In 6200 propensity-matched pairs, in-hospital mortality was comparable between the two cohorts (odds ratio 1.01 [95% confidence interval 0.94–1.08]). Right heart catheterization was used in 12.5% of non-PAC admissions and was a marker of greater severity but did not indicate worse outcomes. Conclusions In AMI-CS, there was a 75% decrease in PAC use between 2000 and 2014. Admissions receiving a PAC were a higher risk cohort with worse clinical outcomes.

Background: There are limited data on complications in acute myocardial infarction (AMI) admissions receiving extracorporeal membrane oxygenation (ECMO). Methods: Adult (>18 years) admissions with AMI receiving ECMO support were identified from the National Inpatient Sample database between 2000 and 2016. Complications were classified as vascular, lower limb amputation, hematologic, and neurologic. Outcomes of interest included temporal trends, in-hospital mortality, hospitalization costs, and length of stay. Results: In this 17-year period, in ~10 million AMI admissions, ECMO support was used in 4608 admissions (<0.01%)—mean age 59.5 ± 11.0 years, 75.7% men, 58.9% white race. Median time to ECMO placement was 1 (interquartile range [IQR] 0–3) day. Complications were noted in 2571 (55.8%) admissions—vascular 6.1%, lower limb amputations 1.1%, hematologic 49.3%, and neurologic 9.9%. There was a steady increase in overall complications during the study period (21.1% in 2000 vs. 70.5% in 2016). The cohort with complications, compared to those without complications, had comparable adjusted in-hospital mortality (60.7% vs. 54.0%; adjusted odds ratio 0.89 [95% confidence interval 0.77–1.02]; p = 0.10) but longer median hospital stay (12 [IQR 5–24] vs. 7 [IQR 3–21] days), higher median hospitalization costs ($458,954 [IQR 260,522–737,871] vs. 302,255 [IQR 173,033–623,660]), fewer discharges to home (14.7% vs. 17.9%), and higher discharges to skilled nursing facilities (44.1% vs. 33.9%) (all p < 0.001). Conclusions: Over half of all AMI admissions receiving ECMO support develop one or more severe complications. Complications were associated with higher resource utilization during and after the index hospitalization.

Background: There are few studies evaluating regional disparities in the care of acute myocardial infarction-cardiogenic shock (AMI-CS). Methods and Results: Using the National Inpatient Sample from 2000 to 2016, we identified adults with a primary diagnosis of AMI and concomitant CS admitted to the United States census regions of Northeast, Midwest, South, and West. Interhospital transfers were excluded. End points of interest included in-hospital mortality, use of coronary angiography, percutaneous coronary intervention, mechanical circulatory support, hospitalization costs, length of stay, and discharge disposition. Multivariable regression was used to adjust for potential confounding. Of the 402 825 AMI-CS admissions, 16.8%, 22.5%, 39.3%, and 21.4% were admitted to the Northeast, Midwest, South, and West, respectively. Higher rates of ST-elevation AMI-CS were noted in the Midwest and West. Admissions to the Northeast were on average characterized by a higher frequency of whites, Medicare beneficiaries, and lower rates of cardiac arrest. Admissions to the Northeast were less likely to receive coronary angiography, percutaneous coronary intervention, and mechanical circulatory support, despite the highest rates of extracorporeal membrane oxygenation use. Compared with the Northeast, in-hospital mortality was lower in the Midwest (adjusted odds ratio [aOR], 0.96 [95% CI, 0.93–0.98]; P <0.001) and West (aOR, 0.96 [95% CI, 0.94–0.98]; P =0.001) but higher in the South (aOR, 1.04 [95% CI, 1.01–1.06]; P =0.002). The Midwest (aOR, 1.68 [95% CI, 1.62–1.74]; P <0.001), South (aOR, 1.86 [95% CI, 1.80–1.92]; P <0.001), and West (aOR, 1.93 [95% CI, 1.86–2.00]; P <0.001) had higher discharges to home. Conclusions: There remain significant regional disparities in the management and outcomes of AMI-CS.

Background: Type 2 myocardial infarction (T2MI) occurs because of an acute imbalance in myocardial oxygen supply and demand in the absence of atherothrombosis. Despite being frequently encountered in clinical practice, the population-based incidence and trends remain unknown, and the long-term outcomes are incompletely characterized. Methods: We prospectively recruited residents of Olmsted County, Minnesota, who experienced an event associated with a cardiac troponin T >99th percentile of a normal reference population (≥0.01 ng/mL) between January 1, 2003, and December 31, 2012. Events were retrospectively classified into type 1 myocardial infarction (T1MI, atherothombotic event), T2MI, or myocardial injury (troponin rise not meeting criteria for myocardial infarction [MI]) using the universal definition. Outcomes were long-term all-cause and cardiovascular mortality and recurrent MI. T2MI was further subclassified by the inciting event for supply/demand mismatch. Results: A total of 5460 patients had at least one cardiac troponin T ≥0.01 ng/mL; 1365 of these patients were classified as index T1MI (age, 68.5±14.8 years; 63% male) and 1054 were classified as T2MI (age, 73.7±15.8 years; 46% male). The annual incidence of T1MI decreased markedly from 202 to 84 per 100 000 persons between 2003 and 2012 ( P <0.001), whereas the incidence of T2MI declined from 130 to 78 per 100 000 persons ( P =0.02). In comparison with patients with T1MI, patients with T2MI had higher long-term all-cause mortality after adjustment for age and sex, driven by early and noncardiovascular death. Rates of cardiovascular death were similar after either type of MI (hazard ratio, 0.8 [95% CI, 0.7–1.0], P =0.11). Subclassification of T2MI by cause demonstrated a more favorable prognosis when the principal provoking mechanism was arrhythmia, in comparison with postoperative status, hypotension, anemia, and hypoxia. After index T2MI, the most common MI during follow-up was a recurrent T2MI, whereas the occurrence of a new T1MI was relatively rare (estimated rates at 5 years, 9.7% and 1.7%). Conclusions: There has been an evolution in the type of MI occurring in the community over a decade, with the incidence of T2MI now being similar to T1MI. Mortality after T2MI is higher and driven by early and noncardiovascular death. The provoking mechanism of supply/demand mismatch affects long-term survival. These findings underscore the healthcare burden of T2MI and provide benchmarks for clinical trial design.

Background: The clinical utility of routine electrocardiographic monitoring following percutaneous coronary interventions (PCI) is not well studied. Methods: We prospectively evaluated the incidence, cost, and the clinical implications of actionable arrhythmia alarms on telemetry monitoring following PCI. One thousand three hundred fifty-eight PCI procedures (989 [72.8%] for acute coronary syndrome and 369 [27.2%] for stable angina) on patients admitted to nonintensive care unit were identified and divided into 2 groups; group 1, patients with actionable alarms (AA) and group 2, patients with non-AA. AA included (1) ≥3 s electrical pause or asystole; (2) high-grade Mobitz type II atrioventricular block or complete heart block; (3) ventricular fibrillation; (4) ventricular tachycardia (>15 beats); (5) atrial fibrillation with rapid ventricular response; (6) supraventricular tachycardia (>15 beats). Primary outcomes were 30-day all-cause mortality. Cost-savings analysis was performed. Results: Incidence of AA was 2.2% (37/1672). Time from end of procedure to AA was 5.5 (0.5, 24.5) hours. Patients with AA were older, presented with acute congestive heart failure or non–ST-segment–elevation myocardial infarction, and had multivessel or left main disease. The 30-day all-cause mortality was significantly higher in patients with AA (6.5% versus 0.3% in non-AA [ P <0.001]). Applying the standardized costing approach and tailored monitoring per the American Heart Association guidelines lead to potential cost savings of $622 480.95 for the entire population. Conclusions: AA following PCI were infrequent but were associated with increase in 30-day mortality. Following American Heart Association guidelines for monitoring after PCI can lead to substantial cost saving.